Will the ground around Whitehouse Station in New Jersey continue to shake in the future? Almost certainly.
In fact, several aftershocks have already occurred. The most recent event occurred near Gladstone, New Jersey, at 5:59 p.m. ET, with a preliminary magnitude of 4.0 and was reportedly felt throughout the region, according to the United States Geological Survey.
Previous aftershocks were around magnitude 2.0 and barely perceptible to people standing right next to the epicenter.
Larger aftershocks are also possible.
The USGS predicts there is a 45% chance of an aftershock of magnitude 3 or greater occurring next week. Next year, the probability increases to 66%.
Is this a harbinger of a devastating earthquake? It may be possible, but it is unlikely.
Large earthquakes of magnitude 7 or higher are often preceded by mild earthquakes. But so far, seismologists have not been able to identify distinctive features of specific earthquakes that could warn that a larger one is imminent.
If a devastating earthquake occurs next week, seismologists will retroactively call Friday's shaking a foreshock. However, there is no way to confidently predict when a large earthquake will occur.
Seismologists also know that large earthquakes are rare in this part of the world. According to a 2008 study by scientists at Columbia University's Lamont-Doherty Earth Observatory, in the New York City area, an earthquake of magnitude 5 occurs approximately once every 100 years, an earthquake of magnitude 6 or greater occurs approximately once every 670 years, and an earthquake of magnitude 7 occurs approximately once every 100 years. It has been shown to occur. Once every 3,400 years.
This is reflected in the Geological Survey's aftershock forecast, which currently says there is less than a 1% chance of an earthquake of magnitude 6 or greater following Friday's quake. The probability of a magnitude 5 earthquake occurring is only 3% next week and 8% next year.
Forecasts are updated as the instruments measure new seismic data.
John Keefe contributed to the report.